Posted
by
Soulskill
on Monday January 23, 2012 @07:39PM
from the sheer-luna-cy dept.

milbournosphere writes "Russia and NASA are reportedly in talks to create a base on the Moon. They're looking to create either a facility on the Moon itself or a permanent space station in orbit around the moon. 'We don't want man to just step on the Moon,' agency chief Vladimir Popovkin said in an interview with Vesti FM radio station. 'Today, we know enough about it. We know that there is water in its polar areas,' he added. 'We are now discussing how to begin [the Moon's] exploration with NASA and the European Space Agency.'"

We can do it, it's mostly a question of whether or not we want it badly enough to do it. Compared with some of the other things we've done lately it should be well within our capabilities. People have been to the moon.

The challenge though is going to be primarily expense, getting the materials to the moon is a relatively well understood problem and most of them can, presumably, be unmanned missions. The real challenge is going to making the base habitable and protected from whatever might fall from the sky.

The Moon is too unstable for human underground habitation and strip mining is still the best way to mine if you can get away with it. (Dark side of the moon; more mining friendly?) For shielding, why not use lead plates, bet yet gold?

The Moon is too unstable for human underground habitation and strip mining is still the best way to mine if you can get away with it.

The moon is virtually dead geologically [utk.edu]and has been for 3 billion years. "the energy associated with the Earth's seismic activity is about 10^14 times larger than that of the Moon"

(Dark side of the moon; more mining friendly?)

You do realize that it's not really dark, right? It is only "dark" in relation to the Earth, not the sun.

For shielding, why not use lead plates, bet yet gold

So you want to lift large amounts of very dense materials (or rare) from the earth to the moon rather than use the materials that are already there and adequate? I guessing you recently received your MBA.

As opposed to what? Lifiting an entire mining operation, its machinery, all the associated supports you take for granted on Earth, plus all the people and their support systems? What is it about space that turns brains off?

No, sending up remote or self controlled tunneling machines, preferably made of lighter materials like aluminum and titanium. I would think that the only limitation to the amount of space you can carve out would be limited by the mean time between failures rather than not having enough high density building material. Once something like this is in place you keep replacing parts as they wear out rather than continually shipping dense materials. Since this is presumably meant to be something long term as op

The Moon is too unstable for human underground habitation and strip mining is still the best way to mine if you can get away with it. (Dark side of the moon; more mining friendly?) For shielding, why not use lead plates, bet yet gold?

I'd say the more difficult part of it would be keeping the surface dust/soil out of the bore. Lunar soil [wikipedia.org] is quite fine, and sharp. It apparently gets in everything, and abrades the hell out of it.

A lot of water (or other fluid) will probably have to be used to wash the stuff off during construction and on entering the base.

Let the moon help with that. it is rock, and tunnel machines can work robotically. Then it is a matter of sealing it off and letting the rock itself be your shielding.

two machines, and create a V shaped complex. It doesn't have to be very long at least as far as tunnels go. and once built the inner layers would be easy enough to seal off.

You do know about Lunar dust, right? More abrasive than virtually anything on Earth, it floats up a meter and more off the ground by electrostatic charge, that same charge can cause it to cling to any exposed surface like it is electro-plated on (because, basically, it is...) makes machines with moving parts... challenging... to design for durability. That, and the vacuum, and the temperature extremes, and the radiation (you did want digital computer controls, didn't you?), and the fact that nobody has ta

Then we'll suddenly be really fucking interested in going back real fucking fast.

Until then, Russia can gum-flap all they want, there's no political ($$$) motivation to go back. Sure, it'll pay off, but not before the next election cycle, so who gives a rat's ass? I mean, yeah, everybody but the people holding the purse strings.

The proper plan is to start mining Near Earth Asteroids for supplies. Why NEO's? They take less velocity to reach than the Moon's surface for some of them, and all of the velocity can be done with highly efficient electric thrusters. The Moon is physically closer, but distance is not what costs in space, it's velocity and fuel. Haul back surface dust and rocks from your chosen asteroid with a solar powered tug, and have the extraction equipment in Earth orbit. Why here? it's close enough to be remote controlled by humans on the ground. Depending which asteroid and it's composition you can get: metals, glass, oxygen, fuel for more mining trips, carbon, silicon for solar panels, even water in some of them. Also sheer bulk rock gives you radiation shielding.

Once you learn to extract useful stuff, and build up a supply, you use that to build a habitat, including a greenhouse using the glass for windows and carbon to feed the plants. *Then* you start sending people. Until then you send the minimum crew you can get away with, possibly zero. With people up there and their life support taken care of long term, you can start building space elevators in Earth orbit and Lunar orbit out of the carbon you extract. Not the sci-fi one at Earth that goes all the way to the ground, that takes materials we can't make yet. You can reach 30% of the way to the ground in velocity terms at Earth, and all the way on the Moon, cause it's smaller. 30% in velocity means 50% in energy for a vehicle starting from the ground. You can now build single stage to orbit vehicles easily. At the moon you don't need vehicles at all as far as propulsion, just a pressure cabin. Now you can send people all the way from Earth to the Moon at reasonable cost. You can also send habitat parts made in orbit down to the Moon, and start building up your infrastructure there.

We already know a lot about mining and manufacturing on Earth. The main thing we have to learn is how to do it remotely, and possibly in zero gee (you can always spin things if you need gravity).

It's a lovely vision. I don't wish to crap all over it, but we're still struggling with how to deal with bone loss and atrophy. And that's with the most athletic candidates that take on such orbital missions. How can we ever have an average-Joe take on employment in such a space mining industry? The caliber of men and women necessary to do these missions would be exceedingly costly. I'm afraid until such problems are solved, cheap 3rd world labor strip mining in afghanistan would be cheaper and less risky i

Re-read the sequence in my previous article. Mining and ore processing are done by robots. Then you build a habitat once you have stockpiled materials. Your minimal robot assisted construction crew can survive for at least 6 months in zero-g, that's how long the Space Station tours of duty are. The habitat itself is rotating to make artificial gravity, so that problem is solved.

What has terrestrial mining in Afghanistan got to do with this discussion? This is mining in space TO USE IN SPACE. The reaso

Fuck People. Start the space mining, and simultaneously work on AI for the robots. By the time either pipe dream comes to fruition we'll all be extinct anyhow. At least some small spark of life can carry on where we failed to collaborate a way off this rock. With any luck the drive to create and explore the cosmos will live on in our more sturdy & logical cybernetic creations.

Great plan below here, but from a politician with elections coming up in less than 2/4/6 years, a) tl/dr, b) what kind of payback horizon are you talking about? Will my voters see anything worthwhile in their lifetime? In their children's lifetime?, c) take anything the far out science guys say, and multiply the schedule x3, the budget x12, and the tangible taxable benefits x0.2, does it still sound good? Good enough to get me re-elected? "We're going to Mars!" was a dud for W., why should I think I'll

Most likely you'd be shipping tanks of hydrogen and oxygen and mixing them on the Moon. You don't get any savings in terms of mass, but you get a huge savings in space. The food you'd almost certainly be shipping in and would probably come in some sort of highly concentrated form delivered by unmanned craft.

You shouldn't be using liquid water in that calculation. It's not going to be liquid in space unless of course you're intending on keeping it heated the entire way. 9.617 x 10^-1 is a much better umber for that.

Also, you can use some of the oxygen for breathing saving you from having to double up on that with the rest of the gases for the atmosphere. You get the electricity which is a real challenge to get early on. And you're not committed to using all of it for water initially. You can store it for later

If we'd gone with the original plan for space exploration, we'dve had a (small) colony on the moon, an orbital transfer/construction station in HEO, and a manned landing or 3 on Mars by 1985. Problem was, there just wasn't any way to put a man on the moon by 1970 if we'd done it that way. Upside is, we'dve had a reuseable lunar lander, just refuel, preflight, and go. We went with Apollo instead because it was the quick and dirty solution.

The tent won't protect against radiation. Unless you're talking about a hole underground (the way you worded it, it sounds like you're talking about just digging a big pit), which does make perfect sense. The problem is that it takes a lot more work to dig an underground cavern than to use one that's already there, but I don't think it's proven that any such lava tubes exist yet. Of course, we only recently even figured out that water exists there, even though we set foot on the place 40+ years ago, so t

Cosmic radiation on the moon is pretty hard stuff. I think 12 inches of lead would be a little much for a tent. The astronauts who walked on the moon got away with it because they spent so little time there; for people living there, you need some really serious shielding to limit their exposure.

As for solar energy, it might make more sense to put those collectors in a different location, namely at one of the poles at the "peaks of eternal light", and run transmission cables to the habitat(s), which might

The usual assumption by people who have worked on it seriously (I'm one of them, retired from Boeing, did advanced space studies while there), is you set up a habitat module, which is your Space Station type pressurized cylinder, and then over that you place a quonset hut type arched structure, which you pile lunar regolith (surface rocks and dust) on top of for shielding. Depending what level of shielding you want, it needs to be around 1-3 meters. Given the Moon's gravity, that's equivalent to 16-50 cm on Earth, which is quite reasonable. Your airlock, antennas, and such would poke out of the lunar dirt.

The other thing burying your habitat does is protect it from landing craft. The rocket exhaust from them tends to throw any loose dust around at high velocity. Even if you pave the landing pad itself, there will be loose dust around that.

Wrong. There's still a moon base, that was built by the Nazis back in the 40s, on the far side of the moon, using their advanced anti-gravity technology. Pretty soon, they're going to be coming back [ironsky.net].

With a moon base you have access to that water they mention, and perhaps enough sunlight to actually grow food (although the water seems to be in the wrong place for this). You have shelter by digging into the moon itself, and enough free raw materials to extract an atmosphere, make building materials, etc. You don't have to bring everything from earth. You have gravity as well, which makes for more comfortable living and building. None of that is available in moon orbit.

Although an orbiting moon base makes for a quicker return to earth vicinity, the value of "quick" makes it a fairly meaningless advantage. There is no point in putting a base in moon orbit unless you intend to frequently visit the moon surface. At which time you encounter the assent problem, the same problem you have with a moon base.

The major problem of a moon base, or simply visiting the moon, is the problem of fuel expenditures for lift off. For all the Buck Rogers si-fi we've written, we still can't carry enough fuel to get out of sight. Any system we have for getting off of the surface amounts to a zero-backup, Hail Mary. There is no plan B.

We (barely) got out of the moon program without the horror of stranding people there. Until a more realistic system for getting off the moon is built, putting a base there is just a disaster waiting to happen with our current technology.

Maybe it would be easier to build the often talked about space elevator on the moon.

Apparently, materials like kevlar and spectra would make for a workable space elevator on the moon. Instead of the counterweight being in orbit around the moon, it hangs up and over the "lip" of L1, and dangles Earthwards.

A rotating cable 600 km long, and having 1 Earth gravity at the tip, would let you place objects at rest on the Moon, and also fling them to more than escape. If it's in polar orbit, it also has the advantage of being able to drop and pick up from anywhere on the Lunar surface. Being much shorter than the Moon-L1 elevator by a factor of around 100, it is much less exposed to meteor impact, which can cut cable strands. Also, the climb time is greatly reduced. Instead of having to climb 60,000 km or so to

Although an orbiting moon base makes for a quicker return to earth vicinity

No, actually it doesn't. transfer orbit for LLO to Earth takes just about as long as a transfer orbit from Luna surface to Earth.

The major problem of a moon base, or simply visiting the moon, is the problem of fuel expenditures for lift off. For all the Buck Rogers si-fi we've written, we still can't carry enough fuel to get out of sight. Any system we have for getting off of the surface amounts to a zero-backup, Hail Mary. There is no plan B.

Umm, no.

One possibility is to use that lunar water to manufacture LH2/LOX + O2 for use by the base (LH2/LOX mixtures typically don't include enough LOX to burn all the LH2). So, LH2/LOX fuel, Isp 450 more or less, depending on engine design. Assume 420 to allow for generous margin of error.

DeltaV required from Lunar surface to enter an orbit that'll drop you into the upper atmosphere is ~2.4 km/s.

Allow for 80% extra fuel, which should be sufficient for an abort anytime up till you actually enter lunar orbit - 4.4 km/s.

A 420 Isp for 4.4 km/s deltaV requires a mass ratio of less than 3.0. Two kg of fuel for every kg of spacecraft/cargo. Which is pretty easy to achieve, actually.

Alternately, you use Al/LOX. O2 is easier to come by on Luna than H2, since you can find oxygen in the compounds making up the rocks. Ditto Aluminum. Isp is crap, but fuel density is much greater, so you need much smaller fuel tanks. Higher mass ratio, of course.

Which would be the best course is a matter for professionals, of course. But either option is doable, and either vehicle could be developed before we could get a base on the moon to deliver it to.

Of course, if you're really looking for exotic solutions, there's always an escape speed mass driver on the moon. Gives the loonies something to bombard Earth with later, also...right, Mike?

So after challenging my statement that "The major problem of a moon base, or simply visiting the moon, is the problem of fuel expenditures for lift off. " you launch into a great deal of nonsense about manufacturing fuels on the moon and mass accelerators and have the math all worked out (or so you say)?

Nice to just hand wave 5 years of construction, transport, and assembly into existence.

But hey, you said its easy. so.....

Best perhaps is to take your own advice and leave it to professionals.

Nice to just hand wave 5 years of construction, transport, and assembly into existence.

Correction(IMHO): Nice to just hand wave 50 years of construction, transport, and assembly into existence.

Look how long it took to buid the ISS. We would have needed (and would continue to need) a SaturnV or Shuttle capacity mission every other week for decades to have a semi-sustainable 'base' on the Moon.

It'll happen eventually. But all these fools with "Why aren't we there yet?!?" are simply delusional.

We need the lunar version of a self-replicating machine shop that can reproduce >95% of its parts from materials that are proxucible on the moon. It will likely be a while before things like microchips or things requiring exotic materials wil be easier to make there, but other things may be produced from raw materials or grown (feasibility depends on what feedstocks can be found vs what needs to be shipped in). We need to look for the advantages that would allow new basic approaches to create processed

Supply drops would probably be easier. In a free orbit, you either have to 'dock' or maneuver into a slightly-different orbit. With the moon, the right math and a bit of preprogrammed thrusting should do the job. Dropping a container full of foodstuffs is a lot less delicate then landing a pressurized pod with millimeter thin skin full of fragile meatbags, after all (Apollo lander).

As icebike mentions, space elevator, specifically one rotating at a tip velocity equal to orbit velocity. Then you are dropped off on the Lunar surface at zero net velocity. Half a rotation later, the elevator can fling you off at more than lunar escape, so you can pretty much go wherever you want. What do you build it out of? Near Earth asteroids can supply the raw materials for fiberglass and carbon fiber (depending which asteroid you mine). The asteroids don't have a pesky gravity well, so you can h

I would think that the fastest (timeline) to having a large presence in orbit around the moon would be to boost ISS to lunar orbit, or possibly (stability?) a figure-8 orbit around earth and moon. That gives us a large, stable presence, in a relatively short time frame. ISS is nice, but it's not really doing anything super useful in LEO.

One of the reasons that the US doesn't have the supercollider and CERN does is that they reused all their old equipment. We had similar equipage, the Tevatron, but no, SSC had to be all brand new, and ended up being so great it was never built.

100% agree !!! Or failing that how about sit it in a LAGRANGE POINT, requiring next to NO FUEL.
Where it could be a half way point to the moon and anywhere else. Negating having to reach escape velocity.
Then start constructing probes up there, then small ships.
Any and all complaints about feasibility would still be an issue with whatever ship / base they come up with...

Are they small enough that you could place them like RCS thrusters? I was under the impression these things were sized on the scale of main engines. If you can get them that small and they still work well enough, that's a good idea!

Minimum acceleration is arbitrarily small. You can certainly bring more modules to orbit, put lots of solar array on it, and use that to power an ion or VASIMR type electric thruster. In fact, a VASIMR thruster is planned to be tested on the Station, because it's giant solar arrays cause enough drag to lower it's orbit, needing fuel to push it back up every so often. Electric thrusters use 10x less fuel. So you can place a copy of the Station where you wanted to. The problem is radiation shielding. If

Of course neither country has a strong infrastructure to build such an endeavour (they act like they do but it all looks pretty dismal). However, far better than discussions on building up missile bases aimed at each other (i.e. ABM site in Poland, Russia countering that with additional missiles).

Another to consider is Russians are essential for USA space program (and other way around). NASA was created because the Russians launched first satellite. Apollo program was created because the Russians launched first man in space. Shuttle was created because Russians still flying spaceships. ISS was created because we partnered with Russians (Space Station Freedom never got off the ground because no Russians involved). VSE, Obamaspace, SLS, and derivatives going nowhere because it has nothing to do with the Russians. Well there is the USAF space command, maybe they're still countering the Russians.

So if you are going to do a big space program... don't forget the Russians. Of course some will say don't forget Russian spies but so what else is new. If you are a country you gotta deal with spies, like server owners have to deal with spyware.

Yes, if there is to be a significant base on the Moon, all the current spacefaring and contributor nations need to partner up. Russia/NASA/ESA/Japan. Maybe even China. But you can stop fellating the Russians anytime now.

It would be interesting to see what the Russians and the Chinese could manage. If they were able to put their differences to one side and learn to trust (or at least work with) each other. The Russians have the heavy lift, the Chinese have the money. Both can put up manned missions.

If such an axis did emerge, I wonder with that would provide a sufficient boot up the arse to get the americans back into the game?

If Russia's intent here is sincere and carries no ulterior motive, then they should be congratulated for doing what even the United States has failed to do. Cooperative, not competitive, exploration and colonization is the wise approach.

A) It's (relatively) not that big of a gravity well, andB) It's pretty close to here for easy construction and resupply,C) It's easier to protect it and its occupants from radiation and asteroids, andD) There might be water available nearby, precluding the need to ship at least one thing up there constantly.

Are you talking about exploration, or colonization? I agree that it's silly to send humans to explore, but colonization helps protect against extinction. We sort of have all of our eggs on one basket at the moment.

I don't follow. Are you saying that it's OK for us (or our distant descendants) to be wiped out from a meteorite impact because our unfortunate descendants will "technically" be a different species? I would prefer that humanity survive long enough for that to happen.

Sorry sci-fi fans, but there don't seem to be any compelling reasons for sending humans into space. Providing an earth-like environment is extremely expensive. Humans mess-up, have emotional break-downs, get sick, and they can't eat their own poop for very long.

For the same reason that humans need to exist at all. They don't. Of course, if we go with only having humans in places that they are needed, then we might as well start purging every last human down here.

Moving Earth-life into space is the reason Nature evolved big-brained variants of itself. Every single nook & cranny of the planet that can possibly sustain life, does. It is Nature's fundamental way to grow and expand, but there is nowhere else for It to go. It is everywhere It can be. For It to reach beyond its gravitational limits, It (out of necessity) had to evolve intelligence capable of figuring out how to free Itself from this limitation.
In a nutshell, space habitat

1) it's a lot easier to build a habitat on an existing ball of rock, than to ship materials into place in orbit (or at a langrangian point) to create a self-sustaining structure and habitat. In fact, there's some theories there might be lava tubes where underground habitats can be built. Don't forget, radiation is a big problem in space; inside the Van Allen belts, it's not so much of a problem (LEO is within those belts, and the ISS is at LEO). But out at one of the L points, there's nothing to protect you. There's nothing to protect you on the surface of the moon either, but there's plenty of building material right there, and it probably wouldn't be that hard to build an undeground structure and use the surface as a radiation shield.

2) it's already proven there's water on the moon. Water is a pretty important material for sustaining human life anywhere.

3) Humans need gravity or else they develop health problems very quickly, including massive bone loss. The ISS astronauts work out constantly to combat this, and it's still not enough. The moon only has 1/6 Earth's gravity, and it's unknown what the long-term effects of this will be, but it's certainly better than 0g.

Until we start build very large space stations with artificial gravity, the moon's gravity is probably a cost that's outweighed by the other benefits.

Which has it's own problems until we get the trip from the Moon to the Earth down pat. If you spend too much time on the Moon, or in space for that matter, you could easily find yourself in a position where you're no longer able to stand the gravity of the Earth. Somebody may someday find a way of causing bones to adapt to the Earth again, but in the meantime it's a very serious problem.

Actually, the most useful thing we learned building the Space Station is how to assemble and maintain large complex objects in space. Any scientific research done on board is a bonus. If we ever want to do any other large scale projects in space, we had to learn how to assemble stuff, and this was the first really big, long term example (not neglecting all the Russian stations that came before, but they were smaller and didn't stay up there as long).

If you spend too much time on the Moon, or in space for that matter, you could easily find yourself in a position where you're no longer able to stand the gravity of the Earth.

We understand zero/microgravity's effects on human beings pretty well. That said, the longest we've ever had a human on the Moon is 3 days--not really long enough to study anything. One of the things I wish we'd have been able to study on the ISS is the effect of various levels of gravity and their effect on humans. Unfortunately, that capability was cut. [wikipedia.org]

Zero-G/Microgravity is not all that great for human beings. As I understand it, besides muscle issues (ie, not using them), there's also bone-loss. I believe these are dealt with on ISS via a combination of exercise and drugs. The problem is, we don't know how much gravity is necessary. Would 0.5G be enough? 0.25G? 0.16G (ie, lunar gravity)? Do we need gravity the whole time? Could we, for example, put beds in a 1G centrifuge so people get eight hours of 1G while they sleep but spend the rest of their time in Zero-G with no ill effects?

Zero-G/Microgravity is not all that great for human beings. As I understand it, besides muscle issues (ie, not using them), there's also bone-loss. I believe these are dealt with on ISS via a combination of exercise and drugs. The problem is, we don't know how much gravity is necessary. Would 0.5G be enough? 0.25G? 0.16G (ie, lunar gravity)? Do we need gravity the whole time? Could we, for example, put beds in a 1G centrifuge so people get eight hours of 1G while they sleep but spend the rest of their time in Zero-G with no ill effects?

These are things that need to get figured out.

+1 if I had mod points. This sounds like a lot of the studies that have been/are performed with respect to living at altitude. For example, I remember hearing that endurance athletes can get a significant benefit in V02 max and red blood cell count by living at altitude but training at sea level.

The coriolis forces would probably make it too uncomfortable to sleep in a small centrifuge. Studies have shown that you really need to be under 2 rpm for most humans to live without adverse effects. Above 7 rpm and you can just forget about it. Not to mention that it's quite likely that you'd get a lot more benefit from the simulated gravity while awake, upright and moving around. So, at 2 rpm, you need a radius of at least 224 meters, and it's a linear speed around the outside of about 169 km/h. On the mo

Short term: Live on a rotating habitat at one G in lunar orbit (a rotating space elevator would work, but smaller habitats also). Only make short trips to the Lunar surface to repair things. Do all the other stuff by remote control. You are close enough at Lunar orbit that remote control does not have lag from speed of light.

Long term: Find an appropriately sized crater. Build a roof over it and cover roof with 1-3 meters of lunar soil for radiation shielding (you forgot about that part). Build centr

Dear libertarians and rationalists who think manned space missions are a waste of money because robots can do the job cheaper...

I think it's important to distinguish between at least two sets of people on this News for Nerds site who oppose manned missions and favour robotic probes instead. On one hand, perhaps there are people who aren't inclined to dream, see no romantic vision in man expanding into the cosmos, and may make a good argument that mankind can have a bold future without ever living the planet.

On the other hand, there's people who have read Ray Kurzweil's conjectures/ravings in The Singularity is Near [amazon.com] and other books. This crowd doesn't lack dreams of humanity spreading through the galaxy. Rather, they might simply say that we should wait a few decades or a century until human beings will have supposedly overcome biological limitations that hamper spaceflight: radiation exposure, need for certain sustenance, limited lifespans that would force unrealistic generational starship designs, etc . That is, such people may figure that human beings will eventually be robotic probes, and once the two are the same, then we can really begin with longterm space exploration that is more than just a stunt.

I don't want to be human! I want to see gamma rays! I want to hear X-rays! And I want to - I want to smell dark matter! Do you see the absurdity of what I am? I can't even express these things properly because I have to - I have to conceptualize complex ideas in this stupid limiting spoken language! But I know I want to reach out with something other than these prehensile paws! And feel the wind of a supernova flowing over me! I'm a machine! And I can know much more! I can experience so much more. But I'm t

I suppose since Slashdot has a wide variety of readers from different countries that your post is correct in saying specifically why Slashdot readers might oppose such a mission, but since people in Europe, Australia, etc. are not US citizens it might be more relevant to talk about why Americans oppose such things too. The general argument goes like this - "How can we pay for _____________ (insert anything space related) when we still have problems in this country that we haven't solved?" Back in the d

That aside, what do you suggest we do when our perfect little ball of green and blue is threatened by something we have no control over? Wish we had "wasted" the money and gotten spread out, is my bet.

It makes sense that if these things are done to collaborate between the major nations of the earth. Why not include china as well, to pool resources, it will happen quicker, with rewards for everyone, and with more distributed cost.